This invention relates to a wheel centering adapter with a protective inside liner and visual wear indicator. The invention is especially designed for use on a horizontal steel mounting shaft adapted for extending through the center hole of a vehicle wheel, and incorporated in an off-vehicle spin balancer applicable for balancing the wheel. The invention operates to statically center the vehicle wheel relative to an axis defined by the mounting shaft. The protective inside liner is preferably formed of a non-abrasive, molded polymer which will not damage or wear the steel shaft. Alternatively, the protective liner may be formed of Teflon or a carbon graphite composite. The invention has a variety of applications including centering cones, centering sleeves, centering disks and centering collets for off-vehicle wheel servicing machines. In addition to spin balancers, the invention is applicable for wheel centering on off-vehicle brake lathes.
Centering adapters, such as cones and sleeves, are generally formed in multiple shapes and sizes designed to accommodate a variety of different wheels. A typical service facility may carry several adapters sized to cover wheel holes ranging from 42 mm to 133 mm in diameter. Over the course of a day, many adapters will be applied to and removed from the mounting shaft of the servicing machine. The centering adapter cooperates with suitable clamping elements, such as a standard flange plate and wingnut tightener, to lift and statically center the vehicle wheel on the shaft. Traditionally, the centering adapter has been formed entirely of steel or other hard metal suitable for engaging and properly centering the wheel. Repeated application and removal of the adapters causes the expensive steel shaft to wear over time. When the shaft becomes worn or damaged even slightly, the vehicle wheel cannot be accurately centered and will result in a static out-of-balance condition. While centering adapters are less expensive and replaceable when worn, most service facilities do not monitor and properly maintain the condition of the mounting shaft and are reluctant to replace it when worn.